Using mathematical morphology to determine left ventricular contours.

abstract：:A phantom study was performed in full-field digital mammography to investigate the opportunity and the magnitude of a possible dose reduction that would leave the image quality above the accepted thresholds associated with some classical phantoms. This preliminary work is intended to lay the groundwork for a future cl...

journal_title：Physics in medicine and biology

authors： Gennaro G,Katz L,Souchay H,Alberelli C,di Maggio C

更新日期：2005-04-21 00:00:00

abstract：:The geometry of a permanent prostate implant varies over time. Seeds can migrate and edema of the prostate affects the position of seeds. Seed movements directly influence dosimetry which relates to treatment quality. We present a method that tracks all individual seeds over time allowing quantification of seed moveme...

journal_title：Physics in medicine and biology

authors： Westendorp H,Nuver TT,Moerland MA,Minken AW

更新日期：2015-10-21 00:00:00

abstract：:A comprehensive set of measurements and calculations has been conducted to investigate the accuracy of the Dose Planning Method (DPM) Monte Carlo code for electron beam dose calculations in heterogeneous media. Measurements were made using 10 MeV and 50 MeV minimally scattered, uncollimated electron beams from a racet...

journal_title：Physics in medicine and biology

authors： Chetty IJ,Moran JM,Nurushev TS,McShan DL,Fraass BA,Wilderman SJ,Bielajew AF

更新日期：2002-06-07 00:00:00

abstract：:Accurate real-time prediction of respiratory motion is desirable for effective motion management in radiotherapy for lung tumor targets. Recently, nonparametric methods have been developed and their efficacy in predicting one-dimensional respiratory-type motion has been demonstrated. To exploit the correlation among v...

journal_title：Physics in medicine and biology

authors： Ruan D,Keall P

更新日期：2010-06-07 00:00:00

abstract：:Short- and long-term side effects following the treatment of cancer with radiation are strongly related to the amount of dose deposited to the healthy tissue surrounding the tumor. The characterization of the radiation field outside the planned target volume is the first step for estimating health risks, such as devel...

journal_title：Physics in medicine and biology

authors： Tessa CL,Berger T,Kaderka R,Schardt D,Burmeister S,Labrenz J,Reitz G,Durante M

更新日期：2014-04-21 00:00:00

abstract：:Preclinical positron emission tomography, combined with magnetic resonance imaging (PET/MRI), is increasingly used as a tool to simultaneously characterize functional processes in vivo. Many emerging preclinical applications, however, are limited by PET detection sensitivity, especially when generating short imaging f...

journal_title：Physics in medicine and biology

authors： Selfridge AR,Cherry SR,Judenhofer MS

更新日期：2018-12-06 00:00:00

abstract：:This note describes a simple phantom which can be used to check the long term stability and accuracy of relative attenuation measurements made by near infra-red (NIR) spectrometers. The phantom has been calibrated, and the results of the calibration are shown to agree with theoretical predictions of the relative atten...

journal_title：Physics in medicine and biology

authors： Firbank M,Delpy DT

更新日期：1994-09-01 00:00:00

abstract：:In magnetic particle imaging (MPI), the relation between the particle distribution and the measurement signal can be described by a linear system of equations. For 1D imaging, it can be shown that the system matrix can be expressed as a product of a convolution matrix and a Chebyshev transformation matrix. For multidi...

journal_title：Physics in medicine and biology

authors： Weber A,Knopp T

更新日期：2015-05-21 00:00:00

abstract：:A method to measure the detector-to-object distance from the images obtained with stationary high-spatial-resolution gamma-ray cameras for in vivo studies has been developed. It exploits the shift of the imaged object in the image plane, obtained at a certain tilt of the parallel-hole collimator. A linear dependence o...

journal_title：Physics in medicine and biology

authors： Uzunov N,Bello M,Boccaccio P,Moschini G,Bollini D,de Notaristefani F

更新日期：2006-05-07 00:00:00

abstract：:There are a number of gel dosimeter calibration methods in contemporary usage. The present study is a detailed Monte Carlo investigation into the accuracy of several calibration techniques. Results show that for most arrangements the dose to gel accurately reflects the dose to water, with the most accurate method invo...

journal_title：Physics in medicine and biology

authors： Taylor ML,Franich RD,Johnston PN,Millar RM,Trapp JV

更新日期：2007-07-07 00:00:00

abstract：:We show how the spectral imaging framework should be modified to account for a high fraction of Compton interactions in low Z detector materials such as silicon. Using this framework, where deposited energies differ from actual photon energies, we compare the performance of a silicon strip detector, including the infl...

journal_title：Physics in medicine and biology

authors： Bornefalk H,Danielsson M

更新日期：2010-04-07 00:00:00

abstract：:Over the course of radiation therapy, a patient's anatomy may change substantially. The relatively recent addition of frequent in-room imaging to assist with patient localization has provided a database of images that may be used to recalculate dose distributions for adaptive radiotherapy purposes. The TomoTherapy Hi-...

journal_title：Physics in medicine and biology

authors： Pukala J,Meeks SL,Bova FJ,Langen KM

更新日期：2011-12-21 00:00:00

abstract：:Recent image guidance developments for preclinical synchrotron microbeam radiotherapy represent a necessary step for future clinical translation of the technique. Image quality can be further improved using x-ray phase contrast, which is readily available at synchrotron facilities. We here describe a methodology for p...

journal_title：Physics in medicine and biology

authors： Pelliccia D,Crosbie JC,Larkin KG

更新日期：2016-08-21 00:00:00

abstract：:Prenatal events such as intrauterine growth restriction and increased cardiovascular risk in later life have been shown to be associated with an increased intima-media thickness (aIMT) of the abdominal aorta in the fetus. In order to assess and manage atherosclerosis and cardiovascular disease risk in adults and child...

journal_title：Physics in medicine and biology

authors： Veronese E,Tarroni G,Visentin S,Cosmi E,Linguraru MG,Grisan E

更新日期：2014-11-07 00:00:00

abstract：:In this paper, Novikov's inversion formula of the attenuated two-dimensional (2D) Radon transform is applied to the reconstruction of attenuated fan-beam projections acquired with equal detector spacing and of attenuated cone-beam projections acquired with a flat planar detector and circular trajectory. The derivation...

journal_title：Physics in medicine and biology

authors： Huang Q,Zeng GL,You J,Gullberg GT

更新日期：2005-05-21 00:00:00

abstract：:In this paper, we use a more realistic head model with ovoid geometry for approximation of a human head. By inverting the Geselowitz equation, some analytic results on the inverse MEG problem are presented in homogenous ovoid geometry. On one hand, some information about the components of primary current is shown by t...

journal_title：Physics in medicine and biology

authors： Peng L,Cheng J,Jin L

更新日期：2006-11-07 00:00:00

abstract：:A function called Gx(L) was introduced by the International Commission on Radiation Units and Measurements (ICRU) Report-87 to facilitate measurement of cumulative dose for CT scans within long phantoms as recommended by the American Association of Physicists in Medicine (AAPM) TG-111. The Gx(L) function is equal to t...

journal_title：Physics in medicine and biology

authors： Abuhaimed A,Martin CJ,Sankaralingam M,Gentle DJ

更新日期：2015-07-21 00:00:00

abstract：:A water calorimeter has been used for the direct measurement of absorbed dose to water in a d(15) + Be neutron beam. The absorbed dose measured with the calorimeter was compared with that measured with an Exradin ionisation chamber, constructed of A-150 plastic. The doses measured by the ionisation chamber were calcul...

journal_title：Physics in medicine and biology

authors： Galloway G,Greening JR,Williams JR

更新日期：1986-04-01 00:00:00

abstract：:Numerous studies have reported the measurements of the dielectric properties of the skin. Clarifying the manner in which the human body interacts with electromagnetic waves is essential for medical research and development, as well as for the safety assessment of electromagnetic wave exposure. The skin comprises sever...

journal_title：Physics in medicine and biology

authors： Sasaki K,Wake K,Watanabe S

更新日期：2014-08-21 00:00:00

abstract：:We study the spatial distributions of beta(+)-activity produced by therapeutic beams of (3)He and (12)C ions in various tissue-like materials. The calculations were performed within a Monte Carlo model for heavy-ion therapy (MCHIT) based on the GEANT4 toolkit. The contributions from positron-emitting nuclei with T(1/2...

journal_title：Physics in medicine and biology

authors： Pshenichnov I,Larionov A,Mishustin I,Greiner W

更新日期：2007-12-21 00:00:00

abstract：:Scanned ion pencil beams carry a low-dose envelope which can extend up to several centimeters from the individual beam central axis. Depending on the energy and species of the beam, this halo consists mainly of secondary particles produced by nuclear interactions in the target or of particles undergoing multiple Coulo...

journal_title：Physics in medicine and biology

authors： Schwaab J,Brons S,Fieres J,Parodi K

更新日期：2011-12-21 00:00:00

abstract：:Simultaneous thermoradiotherapy has been shown to maximize the effect of hyperthermia as a radiation sensitizer in cancer treatment. Here we follow our previous work on feasibility of thermoradiotherapy with the scanning ultrasound reflector linear array system (SURLAS) and TomoTherapy HiArt treatment system, and inve...

journal_title：Physics in medicine and biology

authors： Novák P,Peñagarícano JA,Nahirnyak V,Corry P,Moros EG

更新日期：2008-05-21 00:00:00

abstract：:Dose calculations of pencil beam scanning treatment plans rely on the accuracy of proton spot profiles; not only the primary component but also the broad tail components. Four films are placed at several locations in air and multiple depths in Solidwater® for six selected energies. The films used for the primary compo...

journal_title：Physics in medicine and biology

authors： Lin L,Ainsley CG,McDonough JE

更新日期：2013-09-07 00:00:00

abstract：:Light propagation in a turbid medium is considered using the linear transport equation. The existence of a diffusion length is proved for the Henyey-Greenstein scattering kernel for all absorption ratios. Numerical methods are given that allow accurate computation of the diffusion coefficient quite easily. ...

journal_title：Physics in medicine and biology

authors： Sahni DC,Dahl EB,Sjöstrand NG

更新日期：2003-12-07 00:00:00

abstract：:Diffusion tensor - magnetic resonance electrical impedance tomography (DT-MREIT) is an imaging modality to obtain low-frequency anisotropic conductivity distribution employing diffusion tensor imaging (DTI) and magnetic resonance electrical impedance tomography (MREIT) techniques. DT-MREIT is based on the linear relat...

journal_title：Physics in medicine and biology

authors： Sadighi M,Sisman M,Acikgoz BC,Eroglu HH,Eyuboglu BM

更新日期：2021-01-20 00:00:00

abstract：:Over the past few years there has been much interest in the development of three-dimensional dosimeters to determine the complex absorbed dose distribution in modern radiotherapy techniques such as IMRT and IGRT. In routine methods used for three-dimensional dosimetry, polymer gels are commonly used. Recently, a novel...

journal_title：Physics in medicine and biology

authors： Mostaar A,Hashemi B,Zahmatkesh MH,Aghamiri SM,Mahdavi SR

更新日期：2010-02-07 00:00:00

abstract：:Curves relating beam energy, scattering foil thickness, central-axis depth-dose, and beam flatness have been generated using data taken on a Siemens 200A betatron. The curve set allows a single combination of tungsten foil thickness and electron beam energy to be chosen that will provide the optimum depth-dose distrib...

journal_title：Physics in medicine and biology

authors： Marbach JR,Almond PR

更新日期：1981-05-01 00:00:00

abstract：:All dosimetry protocols recommend the use of plane-parallel chambers for dose determination in electron beams with energies below 10-15 MeV. The protocols have assumed chamber perturbation effects to be negligible. The new AAPM Protocol (TG39) includes a cavity replacement factor prepl that differs from unity for some...

journal_title：Physics in medicine and biology

authors： Nilsson B,Montelius A,Andreo P

更新日期：1996-04-01 00:00:00

abstract：:4D cone beam computed tomography (4DCBCT) is an emerging image guidance strategy used in radiotherapy where projections acquired during a scan are sorted into respiratory bins based on the respiratory phase or displacement. 4DCBCT reduces the motion blur caused by respiratory motion but increases streaking artefacts d...

journal_title：Physics in medicine and biology

authors： O'Brien RT,Kipritidis J,Shieh CC,Keall PJ

更新日期：2014-10-07 00:00:00

abstract：:Skin toxicity has been reported for IMRT of head and neck cancer. The purpose of this study was to investigate the dose in the build-up region delivered by a 6 MV treatment plan for which important skin toxicity was observed. We also investigated if the different designs of the treatment head of an Elekta and a Varian...

journal_title：Physics in medicine and biology

authors： Paelinck L,De Wagter C,Van Esch A,Duthoy W,Depuydt T,De Neve W

更新日期：2005-02-07 00:00:00